.\" Copyright (C) 2022 Jens Axboe <axboe@kernel.dk>
.\"
.\" SPDX-License-Identifier: LGPL-2.0-or-later
.\"
.TH io_uring_prep_fallocate 3 "March 13, 2022" "liburing-2.2" "liburing Manual"
.SH NAME
io_uring_prep_fallocate \- prepare a fallocate request
.SH SYNOPSIS
.nf
.B #include <fcntl.h>
.B #include <liburing.h>
.PP
.BI "void io_uring_prep_fallocate(struct io_uring_sqe *" sqe ","
.BI "                             int " fd ","
.BI "                             int " mode ","
.BI "                             off_t " offset ","
.BI "                             off_t " len ");"
.fi
.SH DESCRIPTION
.PP
The
.BR io_uring_prep_fallocate (3)
function prepares a fallocate request. The submission queue entry
.I sqe
is setup to use the file descriptor pointed to by
.I fd
to start a fallocate operation described by
.I mode
at offset
.I offset
and
.I len
length in bytes.

This function prepares an async
.BR fallocate (2)
request. See that man page for details.

.SH RETURN VALUE
None
.SH ERRORS
The CQE
.I res
field will contain the result of the operation. See the related man page for
details on possible values. Note that where synchronous system calls will return
.B -1
on failure and set
.I errno
to the actual error value, io_uring never uses
.IR errno .
Instead it returns the negated
.I errno
directly in the CQE
.I res
field.
.SH SEE ALSO
.BR io_uring_get_sqe (3),
.BR io_uring_submit (3),
.BR fallocate (2)
